With Patch 4.3, Blizzard includes the Equipped Item Level in their own Item Level stat line. Thus this is another one of my addons which is now obsolete, and will no longer receive any updates.

[Player Frame] Equipped Item Level (PFEIL) is as addon that shows you the
average item level of your equipped items. A new stat line is added in the
General section of your player "paper doll" frame right below the existing
Item Level line. The displayed value for your Equipped Item Level will be
updated whenever you change your currently equipped items.

(Like the normal item level, shirt and tabard are ignored.)